Apparatus for finishing curved-tooth gears



J. E, GLEAsoN Er AL APPARATUS FOR FINISHINLY CURVED TOOTH GEARS Dec. 28 1926.

k-A TToRNEY `Patented Dec. 28, 1926, A

'cali-TED STATES PATENT orifice.

JAMES E. GLEASON AND ALTON P. BLADE, F ROCHESTER, NEW YORK, ASSIG-NORS T0 GLEASON WORKS, OFI-ROCHESTER, NII'SHYYQRIK, A CORPORATION OF NEW YORK.

APPARATUS FOR FINISHING CUBVED-TOOTH GEARS.

' Application illed `llarclx 24, 1923. Serial Ifo. 627,464.

This -invention relates to an apparatus foriinishing curved tooth gears, or what are sometimes called spiral gears, in which the teeth are curved lengthwise acrossthe face of the gear. l

A principal purpose of the invention is to provide for finishin the surfaces of gear teeth by grinding, a ter they have been cut .and hardened, .whereby the will have accurately finished and smoot running profiles.

An additional object of the'improvement is to aiforda practical and efficient mechanism that will finish a geary correctly and in the quickest possible manner, removing any irregularities in the surface of the teeth that may be caused during the hardening process.

With these ends in view, the invention includes the princi les and mechanism that will appear clear y from the following description whenread in con'unction with the accompanying drawings, t e novel features being pointed out in the claim following the specification.

In the drawings:

Figure 1 is plan view, partly in horizontal section, of a machine embodying a practical adaptation of the invention;

Figure 2 is an enlarged plan View of the dressing mechanism for the grinding mem` ber, the latter being broken' away;

Figure 3 is a side elevation of the structure appearing in Figure2;

.Figure 4 is a sectlonal view on the line 4-4 of Figure 2; K

Figure 5 is asectional view on the line 5-5 of Figure 2, and

4Figure 6 is a plan view of the gear blank and grinding member in operative relationshi 'I-)he invention is intended principally for finishing gears of the general type constructed by the mechanism illustrated in Patent No. 1,203,608,November 7 1916, or what are known as curved or4 spiral tooth gears, and while the present disclosure has to do more particularly with bevel gears, the invention in its broader-aspect is applicable equally to bevel or s ur` gears, where the teeth are curved lengt wise across the face of the gear. v

In general the invention includes a grinding member constructed of suitable abrasive material including an annular gear engaging and grinding portion which travels through a tooth space of the gear blank as the grinding member is rotated. The mechanism and principle now to. be described may be carried -out by operating on one or /two toot-h faces at a time by using either one or both curved faces of the grinding member, and the grinding member may be either of the male type, in which case it travels in a tooth space between adjacent teeth, or of the female 'type 'in which ease it may straddle a tooth and operate simultaneously on opposite faces of a single tooth. In order to illustrate a practical embodiment as an example off the invention, this a plication discloses a structure com rising a. ed 1 having suitable curved gui eways in its base in which is mounted a grinder cradle-2 for oscillatory'rolling or generating motion, while 3 designates generally aV gear blank support also arranged on the base 1 and mounted for oscillatory motion about its longitudinal axis so as to permit the necessary relative generating motion between the ear blank and grinding member corresponding to the relative movement of the gear blank on a crown gear, one tooth of which is represented by the grindingelement.

he mechanism for supporting and operatin the cradle 2 and the blank support 3, toto tain the proper coaction between the gear blank and grinder cradle 2, is the same as in the patent above referred to, or may be of other convenient form, and since these motions are well known in the gear generating art and the details of the mechanism for effecting such motions form no part of this invention, it is unnecessary to make any further disclosure. By referring to the above mentioned patent, all parts and movements necessary to effect proper operation of the blank support and grinder cradle will be found.

This invention has to do with the application to the cradle 2 of a grinding member,

which has a gear engaging and grinding portion/1 of annular or face mill form. The grinding member also includes a body or base portion by which it is suitably mounted on a spindle 5 which carries a pulley`6 to which power may be supplied from any suitable s'ource.

' The annular portion 4 is illustrated, see Figure 2, as having converging grinding CII faces, which may operate simultaneously on opposite space bounding faces, or the grinding member may be employed to operate only erating or rolling ,motion between the gearand grinding member, withdrawing Vsaid parts one from the other, and thereafter indexing the gear to bring another tooth space into operative'position, are the same as set forth in the patent previously referred In the preferred operation, according to. the present invention, we take, `a completed gear blank, after it has been Acut and heat treated for hardening, and place'it on the machinel so that the annular portion 4 of the grinding member is located within a tooth space.

tated continuously, and during such rotative action it is traversed back and forth by the oscillatory cradle 2 withA reference to the gear, which at the same time is oscillated about its own axis, and in this manner the proper shape .is imparted to the profile of the tooth. Between successive grinding operations, the blank and grinding member are disengaged and the blank indexedv to present anothei` portion thereof to the grinding member, as usual in gear generating machinery.

The grinding member is dressed by the mechanism that will now be described. Attached to a stationary portion of the frame or cradle on which the grinding spindle 5 is mounted, is a bracket 7 having an arm or extension Sat. its outer end. provided with a circular groove 9, and 410 is a bracket adjustably mounted on the arm 8 by .means of a tongue 11 engaging'said groove 9 and bolts or other 'suitable fastening means by The mechanism and cy-v The grinding member is rowhich the bracket 10 is securefl to the arm -8 in adjusted position.

The bracket 10 includes a pair of guides 12, in the formp of walls arranged parallel respectively to the opposite faces of the annular portion 4 of the grinding member. 13 is a carrier upon which the diamond dresser 14 may be mounted, so as to contact.

with reference to certain structural embodi-v' ments, it is not confined to the particular mechanism or arrangement herein set forth, and this application is intended to cover any modificationsV or adaptations of the apparatus described, that come within the intended purpose of the improvements'or the scope of the following claim.

We claim:A y An automatic machine foraccurately finishing the working surfaces of spiral bevel gears comprising a bevel gear blank support, a rotary annular grinding member including an` enlarged base or .body portion and a reduced grinding portion, said reduced grinding portion Vhaving converging and uninterrupted grinding surfaces affording a rack tooth formation in cross-.section and of circular curvature conforming to the lengthwise curvature of the gear teeth and movable through a curved portion between adjacent teeth, and an oscillatory carrier on which one of said elements is mounted -to produce a relative generating vmovement between the grinding member and bevel gear blank.

In witness whereof, -We have hereunto 'Y signed our names'.

- JAMES 'L 'omas'ou.'v

ALToN P. s LADE. 

